The present invention relates to mechanisms for translating and positioning set finishing apparatus in machines adapted to provide finishing in the way of, e.g., stapling, to a set of sheets produced by an image producing machine, e.g., a copier or a printer.
It is well known in the art to provide set finishing apparatus for machines that produce sheets of paper or other image receiving materials, e.g., printers and copiers, which can position a finishing apparatus, e.g., a stapler, in a plurality of locations, as desired. This may be done, e.g., to corner staple a set of sheets or alternatively to staple the sheets at a plurality of locations along, e.g., one edge of a set of sheets. Typically such apparatus require at least two stapling devices and at least two separate motors and complicated gearing and timing mechanisms that add to the cost of such image producing machines as well as to the footprint of the set finishing portion of the machine. A need exists, therefore, for an improved set finishing apparatus that both reduces the number of finishing devices, e.g., staplers, and the number of motors, as well as reduces the required footprint.
A set finishing apparatus and method adapted for use with an image producing machine discharging sheets of paper in sets that are arranged for finishing is disclosed which may comprise: a moveable set finishing unit having a home position and a plurality of set finishing station positions located generally along a longitudinal axis, and having at least at each finishing station position a retracted position and an operating position, with each respective finishing station retracted position and operating position displaced from each other generally orthogonally to the longitudinal axis; a drive motor having an output drive shaft; a translational drive mechanism comprising a rotating shaft mounted generally parallel to the to the longitudinal axis and operatively connected to the drive motor output drive shaft and adapted to rotate in a rotating direction in response to rotation of the drive motor output drive shaft in a rotating direction; and, the moveable set finishing station being operatively connected to the rotating shaft of the translational drive mechanism in such a way as to be moved sequentially through each of the set finishing station positions and returned to the home position without changing the rotating direction of the drive motor output drive shaft or the rotating direction of the translational drive mechanism rotating shaft. The translational drive mechanism may be adapted to move the moveable set finishing unit out of the retracted position and into the operating position by changing the rotating direction of the drive motor output shaft. The translational drive mechanism rotating shaft may further comprise: an generally cylindrical outer surface of the rotating shaft having formed therein a traveling track groove; and the moveable set finishing unit may further comprise: a traveling track groove follower attached to the moveable set finishing unit and adapted to engage the traveling track groove and move within the traveling track groove when the translational drive mechanism rotating shaft is rotated. The traveling track groove may further comprise: a generally helical groove having a first translational section adapted to move the traveling track groove follower in a first translational direction when the translational drive mechanism rotating shaft is rotated in the rotating direction such that the moveable set finishing station moves in the first translational direction to a position of maximum displacement along the longitudinal axis in the first translational direction and a second translational section adapted to move the traveling track groove follower in a second translational direction generally the reverse of the first translational direction and away from the position of maximum displacement along the longitudinal axis when the translational drive mechanism rotating shaft is continued to rotate in the rotating direction. In at least one of the first translational section and the second translational section the generally helical groove may further comprise at least one generally flattened portion aligned with at least some of the plurality of finishing stations and adapted to permit motion of the traveling track groove follower in a direction generally orthogonal to the longitudinal axis, and the traveling track groove may further comprise a generally flattened portion positioned at the position of maximum displacement in the first translational direction. The position of maximum displacement in the first translational direction may also be one of the plurality of set finishing stations. The apparatus and method may further comprise: a pivotally mounted tray extending generally in the direction of the longitudinal axis, including a wedge plate having a curved lower surface with a curvature that increases the thickness of the wedge plate in the direction of movement of the moveable finishing unit from the retracted position to the operating position; and, a wedge engaging member contained on the moveable finishing unit and adapted to engage the curved surface on the wedge plate as the moveable finishing unit moves in the direction of movement from the retracted position to the operating position, to thereby pivot the pivotally mounted tray away from the moveable finishing unit. The finishing unit may comprises an electrically operated finishing mechanism; and, movement of the moveable finishing unit at a respective finishing station from the retracted position to the operating position mechanically may actuate an electrical switch to operate the moveable finishing unit to perform the finishing operation. The finishing unit may be a stapler.